Many metal roof problems are due to moisture.
Metal roof installed over shingles with 1 board underlayment.
Yes you can install a metal roof over shingles.
However you ll want to check with your local building department before you make any decisions.
Because metal roofs are so light yet so strong metal roofing panels can typically be easily installed over your existing asphalt roof shingles without the need to add structural reinforcement.
Metal roofing weighs less than one pound per square foot.
Make sure the product is designed to be used under metal.
Moisture can infiltrate the underside.
For many applications a layer of plywood underneath your metal roofing is an unnecessary expense.
If you don t want to take our word for it check with your local building department.
3 install 1 4 purlins down over the shingles before installing the metal roof the third way to install a metal roof over shingles is by applying 1 4 purlins over the shingle roof.
Metal roofing panels rated for architectural use attached to purlins horizontal pieces of wood or metal fastened to roofing trusses are structurally sound when installed according to your roofing manufacturer s instructions and local building codes.
In some areas building officials only allow a re roof over one layer of shingles.
Building officials in some areas will only allow a re roof over one layer of shingles while officials in other places may allow you to place the roof over two layers of shingles.
It serves as a moisture barrier as well as a slip sheet.
This type of underlayment is critical to a quality roof installation.
Concerns with metal roofs.
Metal roofing comes in numerous styles that mimic modern architectural shingles unique clay tiles traditional standing seams metal roofs with panels that run vertically up the roof charming wood shakes and more.
We recommend a polypropylene scrim reinforced underlayment made up of multiple layers.
The many style options of metal roofs.
Synthetic underlayment is a roofing accessory created by weaving spinning together polypropylene or polyethylene and a polymer to form an all over protective barrier to put between the roofing material and the roof deck.
This is by far the most common way to install a metal roof.
Synthetic underlayment is a newer innovation that is taking over the metal roofing industry as a better more advanced replacement for felt underlayment.
As long as the plywood under the shingle roof is in good condition this way can provide many benefits.